(CNN)A power outage at Atlanta's Hartsfield-Jackson International Airport, the world's busiest airport, is leaving thousands of passengers stranded and planes grounded indefinitely. The Federal Aviation Administration issued a ground stop for flights to Atlanta at 11:30 a.m. ET Sunday, meaning that planes are being held at their departure airports, according to a tweet on the airport's verified Twitter account. Departures from the airport are delayed because electronic equipment… (www.cnn.com) Ещё...

That was my first question.. UGH, Our SOC has 2 Generators to keep our stuff going so we can keep our flight s moving, but an airport the size of ATL does not???? Something is wrong here.... I would picture then having a couple dozen or more!

Keep in mind folks this was all built in the early 80s and while it should have been address in the updates and renovations over the years it apparently got ignored due to the perceived safety of everything being in a concrete tunnel. Nothing is ever fool proof but I am sure plenty of changes will be made that will last another 30+ years before a different accident will happen and people will wonder why it was ever built that way once again.

Critical institutions like hospitals have power supplies from at least three and often more feeders to a power ring which is also backed up. If any feed goes down there is a momentary drop in power which is redistributed in less than a second. This does not make sense.

I'm curious myself, but from the sounds of the story it's the baggage handling system that's really sinking everything, and maybe also check in kiosks. ATC, runway lighting, radar, and the like could well still be fine. Probably are, in fact. Only the terminals have been reported to be without power, and several cargo flights seem to have gone in and out, per the flight tracking here.

There could be a few things at play: First, airports are generally older than hospitals in the US, so the infrastructure could date to a time when backups were less common. The terminal functions might not be seen as critical to the same degree as hospitals. It might be harder to make updates, since much of that infrastructure, maybe almost all of the high voltage stuff, would be inside the perimeter fence. And also complicated. If something took down a transformer vault or a substation, say, that's on the property it could be hard to even isolate where the failure is, let alone fix it with what could be a very small crew of electricians allowed back there with their tools. There are doubtless numerous transformer vaults and lots of backup power, but the stuff that'd be most critical would be ATC and guidance. Runway lighting. Radar. Glide slope indicators and the like. That's all doubtless backed up as you describe. But the baggage belts? I can see where someone might have overlooked that. And where the place is busy enough that could effectively shut it down. Will be interesting to see what happened here.

Come to think of it, isn't Atlanta entirely dependent on the inter-terminal people movers? It's one thing to back up lighting, HVAC, and a limited amount of critical stuff that runs on household voltage. It's altogether a different proposition to provide a backup for a railroad operating at six hundred volts or more and requiring possibly tens of thousands of amps.

Entirely? No. Heavily? Absolutely. There are hallways which you can walk from terminal to terminal. Most days those hallways have only a smattering of people. One day when the train was broken (unrelated, and only for about 20 minutes) the halls were packed.

And there is your answer: a large underground electrical fire in one substation impacted the switch in the tunnels that would have allowed a transfer to the backup. There is a backup. It was taken out at the chokepoint. They'll fix the switch and have it all up and running as soon as they can pump air into the tunnels and put electricians at the source of the problem.

A "transfer gear switch" caught fire in a "electrical vault tunnel" and the heat burned and melted wiring, including the wiring from a backup source which was right near it..that backup system and wiring should not have been in that tunnel, but I guess it saved $$ to place it there...that plus only 1 backup for the size grid that got knocked out?

Atlanta (CNN)A power outage at the world's busiest airport Sunday left thousands of passengers stranded in dark terminals and in planes sitting on the tarmac, as a ground stop for Atlanta's Hartsfield-Jackson International disrupted air travel across the United States.The outage, which affected all airport operations, started with a fire in a Georgia Power underground electrical facility, Atlanta Mayor Kasim Reed said. The fire's intensity damaged two substations serving the airport, including the airport's "redundancy system" that should have provided backup power, and delayed efforts to contain it, Reed said. Full power was expected to be restored by midnight.

I believe it's two separate power feeds coming from different directions but they meet in the power room (or what is being called the substation because the high-voltage transformers are in there) and that's where the cross-over switch is. The fire was in this room so it compromised the common point of power entry.

It doesnt matter where the feed came from...the redundant system is there to supply power should a problem arise with feed from the substation..emergency back-up systems, were never near the main system for this very reason and the switcher was placed in an electrical utility room, in the complex/building where the power from the feed (in this case that substation) came into the building...2 separate feeds required 2 separate systems

The report I heard was that the very switch that is responsible for diverting power from the main to the backup is what sparked the fire. Doesn't matter where the source of power comes from ... if the switch that makes the magic happen is the cause of the fire the. Ack up systems are irrelevant

The switch gear that failed was in a "vault tunnel", not a "vault room" and it was a transfer switch gear, not from main to backup but from station to station...switch gears trip all the time to route supply/demand loads or for transformer issues requiring it to go offline...that switch gear should have not been there nor should the lines for backup...what took out the backup was A: it being right there instead of separated and B: the heat from the gear failure melted the wires, including those for the backup system, again which should not have been there.Whoever engineered the electrical blueprints, should be getting a kick in the backside along with whoever signed off on it.

I can't tell from this whether the fire was on the airport grounds or not.It sounds like the redundant substations were powered by a single upstream feed. That may change in future. Or not if a cost benefit analysis doesn't pencil out.

One single point of failure at the nation’s busiest airport? No excuses ATL! Multiple power and data feeds are absolutely essential for continuity of operations at modern airports. I’ll bet this glaring vulnerability has been pointed out to ATL officials in the past!